This invention related to an aerofoil having a flow control device commonly known as a air jet vortex generator or AJVG.
An AJVG typically includes a passage within the aerofoil, the passage opening at an upper aerofoil surface of the aerofoil, whereby in use, air from the passage passes through the opening to affect airflow over the upper surface of the aerofoil over at least a range of incidence angles.
An AJVG may be provided to energise boundary airflow over the upper aerofoil surface, to assist the airflow in overcoming a large pressure gradient, which particularly but not exclusively may be encountered at high incidence angles. Thus an AJVG may be used to delay stalling, to increase lift and reduce drag on the aerofoil as the aerofoil moves through the air.
The invention has particularly but not exclusively been developed for use on an aircraft wing, which may be either a fixed wing or a rotating wing such as a helicopter blade.
In order to provide a desired airflow affecting characteristic, the position and shape of the opening in the upper aerofoil surface is critical.